It's high time to make the back cover of smartphones like an e-ink information board. An update speed of 1-2 seconds is enough to receive key information with almost zero energy consumption to maintain the image in bright light. The back cover of all smartphones. should be an e-ink screen covered with a thick layer of protection, because it does not require any touch input - purely a screen to display key information in bright light indoors or outdoors without wasting energy. This is the only improvement in smartphones today that will be really useful to almost all owners.

In addition, reading books/text from such a screen for a long time is orders of magnitude safer. than even with IPS with high-frequency PWM, not to mention the nasty flickering AMOLED screen.

It's high time to combine a smartphone and an eye-safe e-ink reader in one bottle.
At least this will somehow justify the modern idiotic shovel smartphones that cannot be comfortably used in one hand.